Why We Ditched WASM and Went All-In on TypeScript for PitchShow's React Renderer

Look, I need to tell you something embarrassing. Six months ago, I was that person in the engineering meeting saying "Let's rewrite the parser in Rust! WASM is the future!" I'd read all the HackerNews threads. I'd seen the benchmarks. Native code always wins, right? We shipped it. First paint went from 600ms to 850ms . Users started complaining. I wanted to disappear. Then last week, the OpenUI team published their case study: "We rewrote our Rust WASM parser in TypeScript and it got 3x faster." I read it three times. Every paragraph felt like they were describing our exact situation. The boundary tax. The JSON serialization. The memory copies. It was all there. So we did the same thing. We rewrote our entire React rendering pipeline in pure TypeScript. First paint: 850ms → 320ms. Bundle size: 195KB → 112KB. Time to Interactive: 1200ms → 480ms. Here's the story. The data. The mistakes. And why WASM isn't always the answer. The Dream: Rust + WASM = Speed When we started building PitchSh